Multiple issues with apple products

I think that now that you have articulated the problems in writing, you are half way to solving them.

Your problems seem to be a very complex interaction with wifi, bluetooth, and receiving calls and message on multiple devices at the same time. I have some suggestions about things to try in that regard.

One small step toward reducing bluetooth and Wi-Fi traffic might be to connect to the Internet with Ethernet instead.

along there same lines, I suggest you try a wired headset, rather than bluetooth. What computer/phone is it connected to?

if using more wired keyboards and mice, you may be able to adjust sharing and universal control so that it bends to your will.

Universal Control: Use a single keyboard and mouse between Mac and iPad - Apple Support

Bluetooth and wireless+USB devices including USB printers are all competing for the very crowded and interference prone 2.4 GHz band of the Wi-Fi spectrum. Bluetooth headsets as well. WiFi devices assigned to a fixed channel, and Bluetooth moving through the entire 2.4 GHz band using channel--hopping.

My suggestions are an attempt to get more of your stuff OFF that crowded and interference-prone band, and maybe all would work better. Connecting the computers with Ethernet cables could possibly reduce the data in that band.

Having your muse motions appear on the wrong computer suggests you may have activated Universal Control, which Apple might have issued in the ON state by default.

An additional load on the 2.4 GHz band is the possibility even more interference from badly-shielded USB-3 devices:

Why do I have difficulty with Wi-Fi or Bluetooth devices when USB 3 devices are attached to my computer?

Some USB 3 devices can generate radio frequency interference that can cause Wi-Fi and Bluetooth devices operating in the 2.4GHz band to have issues communicating with your computer. Here are some tips to avoid this issue:

• If your USB device has a cable long enough that you can move the device, place it away from your Mac—and make sure not to place it behind your Mac, or near the hinge of its display. The antennas for Wi-Fi and Bluetooth are located there, and USB 3 devices placed there might interfere with your wireless connections.

• If you're using adapters or dongles on a Mac computer with Thunderbolt 3 (USB-C) ports, plug them into the front port on the left side of your Mac, or into the ports on the right side (if your computer has them). These ports are the farthest away from the antennas, making interference less likely.

• To avoid interference on the 2.4GHz band using Wi-Fi, try using the 5GHz band instead. You can change this on your wireless base station. Bluetooth always uses 2.4GHz, so this alternative isn't available for Bluetooth.

from:

About USB on Mac computers - Apple Support

Resolve Wi-Fi and Bluetooth issues caused by wireless interference

Resolve Wi-Fi and Bluetooth issues caused by wireless interference - Apple Support

How is the Cellular reception in your computer-room?

My cellular reception there is really bad, and my Mac and my iPhone encounter a race condition where I get NO notifications on either device when a new message comes in, when expected behavior is BOTH should notify. The messages themselves show up on both devices just fine, but no notifications on either device. My assumption is that both seem to expect the other device to notify, and neither device does.

I thought about my issue when I was reading your complaints about notices, phone calls, and non-performance on your multiple devices in the same room.

My ugly work-around has been to turn off messaging on the Mac. The iPhone notifications then work great, just as expected. I am annoyed at having to type replies on the tiny pretend keyboard. but that is far better than not getting the notifications at all.

if your phone has actually defaulted to mute, you can change the lowest Mute setting to Vibrate. if the phone it is close you your body, you may detect the vibration.

My older phone with only fingerprint reader stayed 'live' much more than expected, and often opened random apps and made settings changes such as reducing volumes. My newer one with face-id does that MUCH more, but that just forces me to be MORE vigilant in making SURE it is closed-down before pocketing it.

That said, I still occasionally feel it getting warm in my pocket, and pull it out to find it is making a movie of the inside of my pocket.

I'm not experiencing that many issues, but I have one that has persisted for several years. Luckily, there's a workaround for it.

what is the distance from your Router to your computer-room.

could you run an Ethernet cable?